Measurement of anisotropy factor of nanoparticle embedded tumor phantoms for plasmonic photothermal therapeutics

Measurement of anisotropy factor (g) in the presence of nanoparticles (NPs) is important for understanding light distribution for plasmonic photothermal cancer therapeutics. Here, anisotropy factor is investigated through bilayer phantoms (epidermal and dermal) of various thicknesses incorporated with gold nanorods (GNRs) concentrations of 10-40 mu g/mL by using in-house developed goniometric setup. Results show that 10 mu g/mL GNRs in the phantom increase g by similar to 50% (g = 0.9471) w.r.t. phantom without NPs. Higher concentrations (40 mu g/mL) of GNRs decrease g by similar to 43% (g = 0.5341) w.r.t. phantom with 10 mu g/mL GNRs. For 40 mu g/mL GNRs phantom, the anisotropy factor reduces by 47% for phantom thickness from 600 to 1800 mu m. Anisotropy factor of GNR embedded phantom increased by 44% by using glycerol (10%-40%). Incorporation of NPs in a tumor significantly affects g, a major parameter for light distribution. These measurements provide insights for light scattering based on nanoparticle doses for plasmonic photothermal therapeutics.